Elevated CK correlates with amount of muscle injury and severity of illness though does not correlate with chances of renal failure or mortality. Usually 5x normal range. Rises 2-12 hours after vent, peaks at 24-72 hours, then drops at about 40% per day afterward.

Myoglobin rises before CPK. Contains heme so urine dipstick will be positive though negative RBCs. About 20% of rhabdo will have myoglobinuremia (Alhedi, 2014). Very specific, though not very sensitive.

BUN/Cr will be lower likely less than 10 due to elevated creatinine rise with muscle breakdown. Look for elevated potassium/phosphate due to muscle cell breakdown.

Urine alkalization (theory is myoglobin which typically causes the nephrotoxicity is worse in acidic environment; sodium bicarb 1amp/1 NS L at 100cc/hr), diuretics, mannitol have no benefit in the ED (or likely at all).

Healthy patients with exertional rhabdo with no co-morbidites can be discharged after oral and IV fluids. Paper looking at patients at risk for severe renal failure only showed if initial creatinine > 1.7 was only true RF (Fernandez, 2005). Also consider >6000 and continuing to trend upward.